Jun 13 – 19, 2015
University of Alberta
America/Edmonton timezone
Welcome to the 2015 CAP Congress! / Bienvenue au congrès de l'ACP 2015!

Adsorption of thiophene-based molecules at passivated silicon surfaces

Jun 17, 2015, 7:18 PM
CCIS Ground Floor PCL lounge (University of Alberta)

CCIS Ground Floor PCL lounge

University of Alberta

Poster (Student, In Competition) / Affiche (Étudiant(e), inscrit à la compétition) Condensed Matter and Materials Physics / Physique de la matière condensée et matériaux (DCMMP-DPMCM) DCMMP Poster Session with beer / Session d'affiches, avec bière DPMCM


Renjie Liu (Lakehead University)


Molecular self-assembly of organic layers at surfaces is a powerful method to achieve the design and fabrication of nanostructures. The self-assembly of large-scale 2-d supramolecular networks at silicon surfaces is a particular challenge due to the large number of dangling bonds which suppress the diffusivity of adsorbed molecules and even break the molecules apart via the formation of Si-C bonds. An essential requirement for the fabrication of high quality organic layers on silicon is passivation of the dangling bonds. We have studied the adsorption of brominated π conjugated tetrathienoanthracene molecules (TBTTA) onto the passivated Si(111)-B surface at room temperature. Thiophene based molecules like TBTTA are of considerable interest in organic semiconductor research due to their efficient conjugation and the chemical stability [1]. The Si(111)-B surface is prepared by annealing highly boron doped silicon wafers under ultrahigh vacuum for extended periods. Annealing leads to boron segregation at the surface. At a maximum boron surface atom concentration of 1/3 of a monolayer (ML) the sample exhibits a √3 × √3R30° reconstruction. This surface has no Si dangling bonds and therefore should provide a high mobility surface for TBTTA adsorption. We will discuss our recent results on the boron surface and compare with our earlier work on the passivated Si(111) √3 × √3-Ag surface. On the silver surface TBTTA molecules are highly mobile and form large 2-d supramolecular domains with a unit cell dominated by relatively weak intermolecular interactions. 1. R. Gutzler et al., Nanoscale 6, 2660-2668 (2014).

Primary author

Renjie Liu (Lakehead University)


Dr Chaoying Fu (McGill University) Prof. Dmitrii Perepichka (McGill University) Mark Gallagher (Lakehead University)

Presentation materials